Add some missing consts in character set handling.

[originally from svn r9291]

charset/charset.h

@@ -98,7 +98,8 @@ typedef struct {
  * U+FFFD (REPLACEMENT CHARACTER).
  */
 
-int charset_to_unicode(char **input, int *inlen, wchar_t *output, int outlen,
+int charset_to_unicode(const char **input, int *inlen,
+                       wchar_t *output, int outlen,
 		       int charset, charset_state *state,
 		       const wchar_t *errstr, int errlen);
 
@@ -121,7 +122,8 @@ int charset_to_unicode(char **input, int *inlen, wchar_t *output, int outlen,
  * output charset).
  */
 
-int charset_from_unicode(wchar_t **input, int *inlen, char *output, int outlen,
+int charset_from_unicode(const wchar_t **input, int *inlen,
+                         char *output, int outlen,
 			 int charset, charset_state *state,
 			 const char *errstr, int errlen);
 

charset/fromucs.c

@@ -40,7 +40,8 @@ static void charset_emit(void *ctx, long int output)
     }
 }
 
-int charset_from_unicode(wchar_t **input, int *inlen, char *output, int outlen,
+int charset_from_unicode(const wchar_t **input, int *inlen,
+                         char *output, int outlen,
 			 int charset, charset_state *state,
 			 const char *errstr, int errlen)
 {

charset/toucs.c

@@ -46,7 +46,8 @@ static void unicode_emit(void *ctx, long int output)
     }
 }
 
-int charset_to_unicode(char **input, int *inlen, wchar_t *output, int outlen,
+int charset_to_unicode(const char **input, int *inlen,
+                       wchar_t *output, int outlen,
 		       int charset, charset_state *state,
 		       const wchar_t *errstr, int errlen)
 {

putty.h

@@ -1080,9 +1080,9 @@ extern char ver[];
 #endif
 /* void init_ucs(void); -- this is now in platform-specific headers */
 int is_dbcs_leadbyte(int codepage, char byte);
-int mb_to_wc(int codepage, int flags, char *mbstr, int mblen,
+int mb_to_wc(int codepage, int flags, const char *mbstr, int mblen,
 	     wchar_t *wcstr, int wclen);
-int wc_to_mb(int codepage, int flags, wchar_t *wcstr, int wclen,
+int wc_to_mb(int codepage, int flags, const wchar_t *wcstr, int wclen,
 	     char *mbstr, int mblen, char *defchr, int *defused,
 	     struct unicode_data *ucsdata);
 wchar_t xlat_uskbd2cyrllic(int ch);

unix/gtkwin.c

@@ -690,7 +690,8 @@ gint key_event(GtkWidget *widget, GdkEventKey *event, gpointer data)
 	 */
 	output_charset = CS_UTF8;
 	{
-	    wchar_t widedata[32], *wp;
+	    wchar_t widedata[32];
+            const wchar_t *wp;
 	    int wlen;
 	    int ulen;
 
@@ -1638,7 +1639,7 @@ void write_clip(void *frontend, wchar_t * data, int *attr, int len, int must_des
      * if we aren't in direct-to-font mode using the D800 hack.
      */
     if (!inst->direct_to_font) {
-	wchar_t *tmp = data;
+	const wchar_t *tmp = data;
 	int tmplen = len;
 	XTextProperty tp;
 	char *list[1];

unix/uxucs.c

@@ -21,7 +21,7 @@ int is_dbcs_leadbyte(int codepage, char byte)
     return 0;			       /* we don't do DBCS */
 }
 
-int mb_to_wc(int codepage, int flags, char *mbstr, int mblen,
+int mb_to_wc(int codepage, int flags, const char *mbstr, int mblen,
 	     wchar_t *wcstr, int wclen)
 {
     if (codepage == DEFAULT_CODEPAGE) {
@@ -59,7 +59,7 @@ int mb_to_wc(int codepage, int flags, char *mbstr, int mblen,
 				  NULL, NULL, 0);
 }
 
-int wc_to_mb(int codepage, int flags, wchar_t *wcstr, int wclen,
+int wc_to_mb(int codepage, int flags, const wchar_t *wcstr, int wclen,
 	     char *mbstr, int mblen, char *defchr, int *defused,
 	     struct unicode_data *ucsdata)
 {
@@ -162,7 +162,8 @@ int init_ucs(struct unicode_data *ucsdata, char *linecharset,
      * in the line codepage into Unicode.
      */
     for (i = 0; i < 256; i++) {
-	char c[1], *p;
+	char c[1];
+        const char *p;
 	wchar_t wc[1];
 	int len;
 	c[0] = i;
@@ -216,7 +217,8 @@ int init_ucs(struct unicode_data *ucsdata, char *linecharset,
      * simply CP437.
      */
     for (i = 0; i < 256; i++) {
-	char c[1], *p;
+	char c[1];
+        const char *p;
 	wchar_t wc[1];
 	int len;
 	c[0] = i;

windows/winucs.c

@@ -1204,7 +1204,7 @@ void get_unitab(int codepage, wchar_t * unitab, int ftype)
     }
 }
 
-int wc_to_mb(int codepage, int flags, wchar_t *wcstr, int wclen,
+int wc_to_mb(int codepage, int flags, const wchar_t *wcstr, int wclen,
 	     char *mbstr, int mblen, char *defchr, int *defused,
 	     struct unicode_data *ucsdata)
 {
@@ -1242,7 +1242,7 @@ int wc_to_mb(int codepage, int flags, wchar_t *wcstr, int wclen,
 				   mbstr, mblen, defchr, defused);
 }
 
-int mb_to_wc(int codepage, int flags, char *mbstr, int mblen,
+int mb_to_wc(int codepage, int flags, const char *mbstr, int mblen,
 	     wchar_t *wcstr, int wclen)
 {
     return MultiByteToWideChar(codepage, flags, mbstr, mblen, wcstr, wclen);